diff --git a/app/src/main/java/com/hieuwu/groceriesstore/presentation/authentication/signin/SignInScreen.kt b/app/src/main/java/com/hieuwu/groceriesstore/presentation/authentication/signin/SignInScreen.kt
index 9ce570d1..4992a214 100644
--- a/app/src/main/java/com/hieuwu/groceriesstore/presentation/authentication/signin/SignInScreen.kt
+++ b/app/src/main/java/com/hieuwu/groceriesstore/presentation/authentication/signin/SignInScreen.kt
@@ -28,6 +28,7 @@ import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
@@ -41,6 +42,10 @@ import androidx.compose.ui.unit.dp
 import androidx.hilt.navigation.compose.hiltViewModel
 import com.hieuwu.groceriesstore.R
 import com.hieuwu.groceriesstore.presentation.authentication.composables.IconTextInput
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
 
 @Composable
 fun SignInScreen(
@@ -50,6 +55,8 @@ fun SignInScreen(
     viewModel: SignInViewModel = hiltViewModel()
 ) {
     val snackbarHostState = remember { SnackbarHostState() }
+    val coroutineScope = rememberCoroutineScope()
+
     LaunchedEffect(Unit) {
         viewModel
             .showAccountNotExistedError
@@ -127,7 +134,17 @@ fun SignInScreen(
                 )
                 Button(
                     modifier = Modifier.fillMaxWidth(),
-                    onClick = { viewModel.signIn() },
+                    onClick = {
+                        if (viewModel.isValidEmail())
+                            viewModel.signIn()
+                        else {
+                            coroutineScope.launch {
+                                withContext(Dispatchers.Main){
+                                    snackbarHostState.showSnackbar("Invalid Email address!")
+                                }
+                            }
+                        }
+                    },
                     colors = ButtonDefaults.buttonColors(containerColor = colorResource(id = R.color.colorPrimary)),
                 ) {
                     Text("Sign in")
diff --git a/app/src/main/java/com/hieuwu/groceriesstore/presentation/authentication/signin/SignInViewModel.kt b/app/src/main/java/com/hieuwu/groceriesstore/presentation/authentication/signin/SignInViewModel.kt
index 418ff7fd..c6ebe231 100644
--- a/app/src/main/java/com/hieuwu/groceriesstore/presentation/authentication/signin/SignInViewModel.kt
+++ b/app/src/main/java/com/hieuwu/groceriesstore/presentation/authentication/signin/SignInViewModel.kt
@@ -1,5 +1,6 @@
 package com.hieuwu.groceriesstore.presentation.authentication.signin
 
+import android.util.Patterns.EMAIL_ADDRESS
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import com.hieuwu.groceriesstore.domain.usecases.SignInUseCase
@@ -40,6 +41,10 @@ class SignInViewModel @Inject constructor(
         _password.value = newPassword
     }
 
+    fun isValidEmail(): Boolean {
+        return EMAIL_ADDRESS.matcher(_email.value).matches()
+    }
+
     fun signIn() {
         viewModelScope.launch {
             when (signInUseCase(
diff --git a/app/src/main/java/com/hieuwu/groceriesstore/presentation/authentication/signup/SignUpScreen.kt b/app/src/main/java/com/hieuwu/groceriesstore/presentation/authentication/signup/SignUpScreen.kt
index f91893be..5024bb22 100644
--- a/app/src/main/java/com/hieuwu/groceriesstore/presentation/authentication/signup/SignUpScreen.kt
+++ b/app/src/main/java/com/hieuwu/groceriesstore/presentation/authentication/signup/SignUpScreen.kt
@@ -28,6 +28,7 @@ import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
@@ -40,12 +41,19 @@ import androidx.compose.ui.unit.dp
 import androidx.hilt.navigation.compose.hiltViewModel
 import com.hieuwu.groceriesstore.R
 import com.hieuwu.groceriesstore.presentation.authentication.composables.IconTextInput
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
 
 @Composable
-fun SignUpScreen(modifier: Modifier = Modifier,
-                 viewModel: SignUpViewModel = hiltViewModel()) {
+fun SignUpScreen(
+    modifier: Modifier = Modifier,
+    viewModel: SignUpViewModel = hiltViewModel()
+) {
 
     val snackbarHostState = remember { SnackbarHostState() }
+    val coroutineScope = rememberCoroutineScope()
 
     LaunchedEffect(Unit) {
         viewModel.showSignUpSuccessMessage.collect {
@@ -137,7 +145,17 @@ fun SignUpScreen(modifier: Modifier = Modifier,
                 )
                 Button(
                     modifier = Modifier.fillMaxWidth(),
-                    onClick = { viewModel.createAccount() },
+                    onClick = {
+                        if (viewModel.isValidEmail()) {
+                            viewModel.createAccount()
+                        } else {
+                            coroutineScope.launch {
+                                withContext(Dispatchers.Main) {
+                                    snackbarHostState.showSnackbar("Invalid Email address!!")
+                                }
+                            }
+                        }
+                    },
                     colors = ButtonDefaults.buttonColors(containerColor = colorResource(id = R.color.colorPrimary)),
                 ) {
                     Text("Sign up")
diff --git a/app/src/main/java/com/hieuwu/groceriesstore/presentation/authentication/signup/SignUpViewModel.kt b/app/src/main/java/com/hieuwu/groceriesstore/presentation/authentication/signup/SignUpViewModel.kt
index 20fb8372..02efe9d9 100644
--- a/app/src/main/java/com/hieuwu/groceriesstore/presentation/authentication/signup/SignUpViewModel.kt
+++ b/app/src/main/java/com/hieuwu/groceriesstore/presentation/authentication/signup/SignUpViewModel.kt
@@ -1,5 +1,6 @@
 package com.hieuwu.groceriesstore.presentation.authentication.signup
 
+import android.util.Patterns.EMAIL_ADDRESS
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import com.hieuwu.groceriesstore.data.repository.UserRepository
@@ -50,6 +51,10 @@ class SignUpViewModel @Inject constructor(private val userRepository: UserReposi
         _name.value = text
     }
 
+    fun isValidEmail(): Boolean {
+        return EMAIL_ADDRESS.matcher(_email.value).matches()
+    }
+
     fun createAccount() {
         viewModelScope.launch {
             val result = userRepository.createAccount(_email.value, _password.value, _name.value)